Wireless electric signaling system.



No. 813,914; PATENTED FEB. 27, 1905.

, R. H. RVENDAHL. WIRELESS ELECTRIC SIGNALING SYSTEM.

APPLIOATIQNFILED AUG. 19. 1905.

Fig.1 E 12 3 V serve as a measureor scale orthe existing DAHL, engineer, a subject'of the Kingzof Swedicator in most cases must be iiiserted'f'in a case, lie alone withthe self-induction mil in Bit from'one-circuit I connected with abreaking 1'1- RAGNAR H. REND'AH'L, QEBERLIN, GERMANY.

WIRELESS ELECTRIC Specification of Letters Patent.

SIGNALING SYSTEM.

Patented Feb. 27, 1906.

Application filed Augustlll, 1905. Serial 1%. 274,904.

To all whom it may concern: I

Be it known that I, RAGNAR 'HAKAN REN den and Norway, re'sidingat 13 Hollmann strasse, Berlin, S. W., Germany, have invent ed certain new and usefulImprovements Wireless Electric Si naling Systems,of which the following is a ll, clear, and exact description, reference being had to the accom- Pi y ng aw g formingL Pa t f this d-- ficatiom .I

In receivers fo'r'wireless telegraphyfthe' in;-

separate oscillation-circuit, the so-called dicatoi-circuit/f wwm is supplied iriductiveljf resonance. The-two circuit mutually tuned, "that'jis"i'to sayjthey order to have as complet'e a energy as'possible. -The travelito jtlieioth' thatinstea'djof the strait-rations tit e-Zia. cuit, two vibrations a rapid and a slow one, take place, which lie the farther apart the more rapid the transference of'the' energy is, that is to say the firmer the coupling (the elec; tric connection) between the circuits is. This breaking up of the waves ma therefore also coupling and the proportion between the dif-- ferenceof the two waves'producedQand the natural wave-is indicated by the 'de-' gree of coupling. This breaking up of the waves in thereceiver produces inexactness in the tuning of the receiver to the transmitter; This, however, had hitherto to be put up with I because a diminution of the breaking u of the waves, that is to say making the coup ing looser, always has as a result inthe receiver a diminution of the receivin intensity. This action is mainly to be ascri edflto the proper: ties of the indicators. 7 We differentiate between two indicators 'i. e. between those which respond to potential and which in anon-re s onsive'conditionconsurne no energyg-and those which respond to current air which consume an amount of energy proportionate to the stren th of currentfifloi'ing through them. To t e first class'th so-c-alled coherer belongs, to. the second the electrolyticdetector. These two indicators do not suflice for the conditions for a full utilization of the resonance-if they, as was hithertothe an oscillation-circuit. The coherer forms,

before the calling up, a capacity. This is somewhat variable so that the number of oscillations of. the indicator-circuit is not to be maintained constantly similar to that of the receiver circuit, while the electrolytic detector. consumes too large a part of the oscilla tion energy conveyed through it to-allow of an increase of amplitudeby resonance. If a condenser havm' a capacity 'severaltimes as- I largeasthat of t e indicator be connected in parallel to it,- on the one hand the wave alteration produced by the variations of capacity of the coherer will be unimportant and on the :otherhand withthe electrolytic detector the" I. I major part of the oscillation energy will be i conveyed through the condenser andthus not-consumed. The enlargementof the capacity {off the indicator-circuit alone, how- 4. -.ever, does;nOt-attaintheobject sought for, y

i'becaus'e-a not inconsiderable part of the' o's-' cillation energy is destroyed by ohmic-resisto anceof the self-'induction'coil of the indicator: 1 circuit." A diminution of this resistance is therefore ,also necessary. i Now experiments have shown that when a condenser is eon' nected, in parallel to the indicator and witha suflicient diminution of the ohmic resistanceofthe self-induction coil and the indicatorcircuit, a loosening of the coupling within certain limits has an'increase of the "amplitude 3 in the indicator-circuit as a consequence,that"- is tosay, in other words, that'apureisharp tuning jof'the indicator circuit -1s' p s b without diminishing the receiver intensity in p the indicator-circuit but in fact frequently increasing it: resistance-takes place preferably by a suitable enlargement of the section of the wire used for thejself-induction coil; In order to obtain practically handy dimensions and to The diminution of the ohmic avoid losses by eddy-currents in too thick copper wires, it is preferable to wind the selfinduction coils from a many-times subdivided the maximum in necessary for e'stablis d ut depen: s partly tensity is, not constant,

on the damping of the arrivin wave-train,

partly on the damping whic indicator and without diminished losses of resistance in theindicator-circuit, an intensity is obtained which always increases with the cord. The degree of coupling in the receiver Q l v 513.914

increasing degree of coupling of the receiver wlule m tuning the receiveraccording to the present invention the intensity first lowers \\'1ll l (lllllllllSlllllg degree of coupling and then, however, again rises and attains a maximum at tllc'given, above-mentioned,'degree of coupling (Ll'tolive' percent.

This invention thus affords the possibility,

by indicatingsuitable means and propor- 1.; lions, of producing asubstantially sharper tuning of the receiver to the arriving wave than wasplreviously the case'withou-t dimi-.

nution of t ereceivmg intensityand thereby obtains a conslderably lngher degree of -v1bral 5 tion freedom ofsthe receiver than it hitherto 'posses sedt- T h inve t ihillh gi f -la i ii ar y scribed; inconnectionj'with t 1e accompany- 2Q The-recivershown in Figure 11 ,is formed of 1 is ,conduc"tively an aerialjfconductolg ld;whic

i e-on y 0 pld rithf n indi t Tl e. o e'co'nplingis here attained clrcutb .7 a by,- f'only-ap 'on of: the; total s'elflinduction 2 5 containedg inythg. receivencircuifi :be ing' e111", P y r qmq r ii w he n tow m it; that is jt'o' saynoth only-a portion i uitfl e s t0- cuit ,andserves vonly to preventa shortcircuiting ofv the local-,"circuit '1', containing the,

battery} h.-

The [self-induction .coil is by the present inventio nf-iforrned of a conductor of goodfconductiyit ;a'nd havinga diameter of at" least one-{ 'meter. 1A, condenser f is 40 connected in-i-parallel'to the coherer, through condenser the capacity. ofthe indicator-circuit is brought to at least twice the amount of the capacity of the coherer. .Instead of loosely eonductivelycoupling the indicator-circuit with the aerial conductor, the coupling may alsotake place inductively, as shown in Fig. 2, the loose coupling being obtained in the ordinary manner, for instance,

rby leaving a space between the primary and the secondary coils of the converter, or by only a smaller portion of the self-induction of the indicator-circuit, acting in conjunction with the primary coil of the aerial conductor.

Having explained my invention, what I claim, and desire to secure by Letters Patent,

1. Areceiver arrangement for wireless electric signaling system in which a condenser is inserted in parallel to the indicator, the caacity of which condenser is at least twice as arge as that of the indicator,- and the damping of the indicator-circuit .is so diminished .by the diminution of its ohmic resistance that adiminution ofthe' degree of coupling between the indicator-,circuit and the receiver circuit within certain limits has for. a conse- '3i181106 an increase of the intensity in the inicatorl circuit substantially as described,

' 2. A wireless electricjsignaling system in I which the coupling between the indicator -circuit and the receiver-circuitis made so 1 loose that the intensity in the indicator-circuit attains a maximum quantity with the object of obtaining a sharper tuning of the re 

